Accomodation tonus in myopia and its potential prognostic value
Tarutta, E.P.; Tarasova, N.A.
Vestnik Oftalmologii 128(2): 34-37
2012
ISSN/ISBN: 0042-465X PMID: 22834235 Document Number: 661026
60 patients with different degree of myopia were examined to study habitual accomodation tonus (HAT) and accomodation rest tonus (ART). HAT was calculated as a difference between standard autorefratometer measurements before and after cycloplegia; HAT in open field (HAT-OF) was estimated using open-field autorefractometer before and after cycloplegia with a patient looking at the distant object; ART was considered as a difference between refraction in dark conditions (dark focus) and cycloplegic refraction using open-field autorefractometer Grand Seiko WR-5100K (Japan). In examined patients ART was maximal (-0,87 +/- 0,08 dpt) and HAT-OF-minimal (-0,15 +/- 0,04 dpt). The high values of accomodation tonus (both HAT and ART) were associated with higher rates of myopia progressing. For the first time dynamic refraction measured using open-field autorefractometer confirmed the phenomenon of "negative" accomodation.